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V 




O R A 



Miuseujm of Compairative Zoology 



Cambridge, Mass, 



29 July, 1966 



Number 248 



A TRIAS^TC AiBIOXITE FROM THE ITTXDUBAGH 
REGION, BALrCHTSTAN, W EST PAKISTAN 

By Berxjiakd Kummel 



Ammnnites are extremely rare in the thiek rlevelopnioTit of 
Triasssie strata between Quetta and Ilindubagli in West Pakistan. 
Only five specimens, mostly very poorly preserved, have been re- 
ported to date. Beeanse of tlieir rarity tlie doeuiiieiitation of one 
additional speeimen of rather good preservation is warranted. 

The first record of Triassic ammonites from this region of 
Baliiebistan was by Mojsisovicrs (1896, p. 611; 1R99, p. 44) who 
described a sin<*]e specimen, collected by C, L- Oriesbach from a 
loose biock, 7 miles south of Ilindubagh. This specimen was 
described as Didyuntis afghanicHS ^Fojsisovics (1896; 1899, ph 
20j fig. 9) and assigned a NotMan age. Vi-edenburg (1904), tni 
tile basis of siirveTS carried out in the summer of 19nl, con- 
tributed some regional, stratigraphie, and paleoutological tlata 
on these Triassic foi^mations. This author reported the presence 
of Monofis ef. saliuaria in fair abnndrnice at a few horizons and 
h}calitie^ and illustrated one specimen. In addition, In^ illustrated 
ail ammonite-//^/^//*//r.>r 8]>. The speciiiK^n was not found in pla<;e 
but from lotvd condititms X'^redenburg conehided tliat it had not 
been transported very far. These specimens plus others collected 
by "^^redenburg were submitted to C. Diener who publisheil his 
results in 190fi. In this small collection Diener (1906) w^is al)le 
to reeognizr tJie following forms : 

Mo ifot is saJ iaar ia Sc blot h e ira 

Halorites sp. ind. aff. subcafenato Mni^^isovics 

Celt it €s sp, ind, (group of 1 acutepUcati) 

Parafibefites sp. ind, ex aff. foniqifisfi ^Mojsisovics 

Ditfmarifes or Disfirhifes ? sp. ind. 

Eh a cop h y f lit es v red e n b u rgi D i en e r 



2 BREVIORA No. 248 

The generall,y poor state of pi^eservatioii of the specMinens avail- 
able to Diener is well relipc^ted in the nneertaint\' in the identi- 
fieations. Of these specimens only Mouotis saliuaria and Jlahwites 
sp, ind. afT. snhcatenato were obtained from the spot where they 
probably weathered out. All the rest of the s]>eeiniens were 
picked iij) amongst transported boulders from the beds of rivers 
witliin the Triassie oulerop area. On the bajsis of this seanty 
data^ both Vredenburg and Diener eoiiebided that the strata en- 
closing these fossils arc of Norlan ajj^e. Additional *>eoh>*?ieal 
observations on the Triassie formations of the Quetta-Hindubagh 
area have been made by Gee (in TTeron, 1939, p. 26-27), by 
Williams (1959)^ and hy the Colombo l*Jan Project (1961), but 
in these reports there is little additiunal paleontologieal data, 

I have bad the opportunity to spend a few days in the region 
between Qnetta and Hindubagii examining these TiMassie forma- 
tions but was not sueeessfn! in finding any fossils. Mr, H. A. 
Eilgrami entrusted to the writer a specimen found in a stream 
l)ed near a mine of the Pakistan Chrome Ltd., two miles east of 
Gwal Railway Station. This specimen is fairly well preserved 
and can be assigned with confidence to Ariefoccflitf s ariefifoides 
Diener, a species firs;t desi^-ibed from the Tropites limestone ex- 
posed at Kalapani, Byans, in the Himalayas. Tliis new specimen 
thus ]>i'n\'Ldes an additional Jiidv in the correlation of tliese Trias- 
sie formations of Balncbistan with the nnich better dixMnuented 
Himalnyan sequence. The Tropifcs limestone of Byans has 
yielded 168 species of invertebrates of which 155 are aunnonites. 
The fauna as a whole shows wry strong affinities to the Upper 
Triassie famias of the Mediterranean regirm. All of the fossil 
s^peeies were collected from a three foot bed of limestone; of 
special interest is tlie mixture in this bed of typical Carnian 
and Norian ammonite species. Since Ariefocelfifc^ ariefifoides 
was a miique species previously kno^vn only in Byans, and its 
presence in a mixed fauna at that, it does not luOp in refining 
the age determination of the Balueliistan Triassie formations. 
Diener 's (1912, p. 150) final words oti the age of these Triassie 
rocks were that they were Norian in age. 



1966 TRTASSIC AMMONITE 3 

SYSTEMATIC DESCKIPTIUX 

Fajiiily TKOriCELTITIDAE Spatli, 1951 

GtMins Arietoceltites Dieiier, 1016 

^\RrET0(:^ELTiTE8 AiiiETiToiDES (Dieiier) 

Fis^ures la, b 

Tropieeltites arietitoides Dieuor, 19(Ni, p. 1^6, pi. 3, fig, 12; Diener, 1912, 
p. 125; Dieiier, 1916, p. 101; Si)atli, \9~A, p. 94; Kinnmel, in Arkell, 
1937, p. L171, fig. 201, 4, 

Tliis species is represented by a single speeipieii of 56.5 mm in 
(liaiiirtri', KM mm for tli(* height of the adoral whorl, 13,8 mm 
for the width, and 35 mm for the diameter of the iimbilieiis. Tn 
degree of iiivohitiou and general proportion, tliis specimen is 
very much like the type speeinp^ii. There are slighl dirt'erenees 
in ornamentation : in the Balnehistan speeimeii the ril)s are 
riisiradiato in the adoral 1.5 volutions, whereas in the Byans 
speeimen the ribs are more radial. In both speeimeiiis the ribs 
tnrn strongly forward on approaehinn- the marginal furrows 
alipniing the np^liaii keel. T do not believe that these differences 
ill ornamentation are of any taxonomic significance. The Byans 
material available to Dieiier (11106) consisted uf the type speci- 
men plus a few fragnu^nts. With this one additional specimen 
there is insufficient data available to evaluate the ranf2:e of vari- 
ability in these features, Iluwever, on the basics uf experience 
with populations of eonipa fable forms, one should expect a range 
of variability that would include that expressed by tho?^e two 
specimens. The suture was onlj- i>artially exposed on Diener^s 
type sperinien and is not preserved in the specimen recorded here. 

Occurrence. — From stream bed near mine of Pakistan Chrome 
Mines Ltd., two miles east of railway station at Gwal, presumably 
from Aluzai groups Ijetween Quetta and Ilindubagh^ West Pak- 
istan, 

Repositorif. — Geological Survey of Pakistan, Quetta, West 
Pakistan, 

Ack}ioichdgei}te}tfs. — I wisli to thank ilr. S, A, Bilgrami for 
the loan of the specimen and for his hospitality duriug a visit to 
Hindubagh, My visit to Pakistan was made possible by the aid 
of Xational Science Foundation Grant Xo. G19066, 



4 BREVIOKA No, 248 

EEFEEENCES 

ArkelLj W. J. et ah 

1957. Treatise oa iiiveitebJiite paleont()lyg\% P^it L, Molhisca 4^ Gepli- 
alop<MlM, Ainmojioidea, Geol, Soc, Am. and Univ. Kaiisns PresSj 
490 pp. 

OoLujiijju I'LAN Project 

]!>(n, KeeoiHiitiisSiUU't' goulo^j of ]!rir1 of West PnkistMO. Toronto, 

55(1 ]>iK 
DiENER, Carl 

liHjij. Jlimalayan fossils, FaunM <if llir in^jAtes LiHii'Mtoju' of Byaiiis, 

India Geol. Hiirw, l\i]aeon1, ludira, (15) 1; l-i*«H, pis. M7. 
1906. Notes on an Ufi|ier Triassie fnuna froin the PiHliin District, 

lialiuliistnn, i.'Olleete<! Ifv E. Viedt jilnn-^- in the yeiw 1901, Rec. 

Genh Surr. Tndin, 34: lli-l^l, i^ls, 3, 4. 
UnM. T\h' Trias of the JliniMhiVMs. Alenj, ({eoL Wiirv. Iniliii, 36: M59, 
1915. Eiiiige Benierkini^ini znr Nonit^nkhitiir dor Trins-oei^halopodeii. 

Centralhl. .Minerah (ieuh Paiiiunt., No. 5: 97 in.l. 
Heron, A. M. 

VJkAK (.iunural report uf the geulogiral survey of Iiidl^i f<M the year 

1938. Rer. (iroh Purv. India, 74: 1-1:12. 
Mojsisovics, E. V. 

1896. Beitriigi^ zur Keniilniss (lev ohertrlnflistdien Ce}ih:ih)poden- 

Eaimen des Hiniahayaft. Denkmdn-. Akad. Wiss. Wieii, 63: nTfi- 

701, pis. l-2li. 
1899. Upper Trinssie Co]>h^sh)|Mjd;i faunae of tlie Hininlny:i. Indi.-i 

Geol. Siirv., Fahieont. Indiea, (l-l) 3: 1-157, jds. 1---. 
Spatii, Ij. F. 

llJ-jL Oatalogne of tlie fossil Cephalopoda in the BritiHli Mn«enni 

(Natural History). P;irt 5, The Anmionoiden of the Trias. 

Loudon, 2*28 pp. 
VhedenbI'RG, E. 

19('4. Oil t!ie oceurrenee of n spec'ies of ifalorites in the Trins of 

Birlurhistaii, Ree. Geol. Surv, India, 31: li)2 IfiO, pL 17, 
Williams, M. Dean 

19'j9. i^t r;i1 igi'apliy of the Lower Indus Btisiii, West Pakistan. Fiftli 

World Petrnhnnn f^ongress. See. 1, Pnper 19: 1 15. 



1966 



TRI ASSIC A M M X 1 TE 



5 





1 



Figure 1, 8ide and veiitiiil view of Ai^ietaciftUt/s arietitoides (Diener) 
fruiii Tria??sic formation near TTindnhagh, West Pakistan, X 1- 



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1966 TRIASSIC AMMONITE 3 

SYSTEMATIC DESCRIPTION 

Family TROPICELTITIDAE Spatii, 1951 

Genus Arietoceltites Diener, 1 91 6 

Arietoceltites arietitoides (Diener) 

Figures la, b 

TropiceJtites arietitoides Diener, 1906, p. 156, pi. 3, fig. 12; Diener, 1912, 
p. 125; Diener, 1916, p. 101; Spath, 1951, p. 94; Kummel, in Arkell, 
1957, p. L171, fig. 201, 4. 

This species is represented by a single specimen of 56.5 mm in 
diameter, 13.1 mm for the height of the adoral whorl, 13.8 mm 
for the widtb, and 35 nnn for the diameter of the umbilicus. In 
degree of involution and general proportion, this specimen is 
very much like the type specimen. There are slight differences 
in ornamentation : in the Baluchistan specimen the ribs are 
rusiradiate in the adoral 1 .5 volutions, whereas in the Byans 
specimen the ribs are more radial. In both specimens the ribs 
turn strongly forward on approaching the marginal furrows 



aligning tine median keel. I do not believe that these differences 
in ornamentation are of any taxonomic significauce. The Byans 
material available to Diener (1906) consisted of the type speci- 
men plus a few fragments. With this one additional specimen 
there is insufficient data available to evaluate the range of vari- 
ability in these features. However, on the Ijasis of experience 
with populations of comparable forms, one should expect a range 
of variability that would include that expressed by these two 
specimens. The suture was only ])artially exposed on Diener 's 
type specimen and is not preserved in the specimen recorded here. 

Occurrence. — From stream bed near mine of Pakistan Chrome 
Mines Ltd., two miles east of railway station at Cwal, presumably 
from Alozai group, Ijetween Quetta and llindubagh. West Pak- 
istan. 

Repository. — Geological Survey of Pakistan, Quetta, West 
Pakistan. 

Ach-nowledgemenis. — I wish to thank ]\lr. S. A. Bilgrami for 
the loan of the specimen and for his hospitality during a visit to 
Hindubagh. '^W visit to Pakistan was made possible by the aid 
of National Science Foundation Grant No. G19066. 



[Begin Page: Page 2] 



4 BREVIORA No. 248 

EEFERENCES 

Arkell, W. J. et al. 

1957. Treatise on iiiveitebiate paleontology, Part L, Mollusca 4, Ceph- 
alopoda, Ammonoldea. Geol. Soc. Am. and Univ. Kansas Press, 
490 pp. 
Colombo Plan Project 

1 961 . Reconnaissance geology of jiart of West Pakistan. Toi'onto, 
55(1 pp. 
DiENER, Carl 

1 90(5. Himalayan fossils. Fauna of the Tropilc.s Limestone of Byans. 

India Geol. Surv., Palaeont. Indiea, (1 5) 1 : 1 -201 , pis. 1 -1 7. 
1 906. Notes on an Upper Triassic fauna from the Pishin District, 
Baluchistan, collected l»y E. YriMh iiliuig in the year 1 901 . Rec. 
Geol. Surv. India, 34: 12-121 , pis. :i, 4. 

1912. Tlie Trias of the Himahiyas. Mem. Geol. Wurv. India, 36: 1-159. 
1916. Einige Bemerkungen zur Nonienklatur der Trias-cephalopoden. 
(•(iitrallil. '^Filulv'll. (ieol. Paliioiit., No. 5: 97-105. 
Heron, A. M. 

1 939. (General leport of the geological survey of India foi- tlie yeai- 
1938. Rec. Geol. Surv. India, 74: 1-132. 
MoJsisovK's, E. V. 



1S9(). Beitriige zur Kenntniss der obertriailischen Cephalopoden- 

Faunen des Himalayas. Denkschr. Akad. Wiss. Wien, 63: 575- 

701, pis. 1-22. 

1 899. Upper Triassic Ceplnaiopoda faunae of tine Himaiaya. indi;i 

Geoi. Surv., Paiaeont. Indiea, (15) 3: 1-157, pis. 1-22. 

Spatin, L. F. 

1951 . Catalogue of the fossil Cephalopoda in Ilic Uiitish Museum 
(Natural History). Part 5, The Annuonoidea of the Trias. 
London, 228])]). 
Vredenburg, E. 

1904. On the occurrence of a species of llnlorites in the Trias of 
Baluchistan. Rec. Geol. Surv. India. 31 : 1 621 66, pi. 1 7. 
Williams, M. Dean 

1959. Stratigraphy of the Lower Indus Basin, West Pakistan. Fifth 
World Petroleum Congress, Sec. 1 , Paper 19: 115. 



[Begin Page: Page 3] 



1966 



TRIASSIC AMMONITE 



Figure 1 . Side and ventrai view of Ariei oceit iies arietitoides (Diener) 
from Triassic formation near Hindubagli, West Pakistan. X 1- 



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